Promoting Effect of Fusicoccin on Seed Germination

Abstract

Abstract The effects of fusicoccin on the germination of dormant, light‐requiring or abscisic acid‐inhibited seeds has been investigated. (1) Fusicoccin (10 −6 M ) induces germination in dormant wheat seeds ( Triticum durum cv. Cappelli; 1972 crop) and stimulates it in seeds already relieved from dormancy (1971 crop), with an effect similar to that of gibberellic acid. (2) Fusicoccin (1.5 × 10 −6 M ) is more active than the two phytohormones gibberellic acid and benzyladenine and than white light in stimulating light‐requiring lettuce seeds ( Lactuca sativa cv. Grand Rapids) to germinate. Germination of radish seeds ( Raphanus sativus ) is also accelerated by fusicoccin, while benzyladenine and gibberellic acid are less active in this material. (3) Fusicoccin (1.5 × 10 −5 M ) removes almost completely the inhibitory effect of abscisic acid on germination of radish and lettuce seeds, whereas benzyladenine (10 −4 M ) and gibberellic acid (3 × 10 −4 M ) remove the inhibition only partially. The possible relationship between these results and previous information on growth by cell enlargement is discussed in terms of the mechanism of action of fusicoccin as compared with natural hormones.